Stephen Warren <swar...@wwwdotorg.org> wrote @ Wed, 30 Oct 2013 23:44:04 +0100:
> > + host1x {
> > + compatible = "nvidia,tegra30-host1x", "simple-bus";
> > + nvidia,memory-clients = <&smmu TEGRA_SWGROUP_HC>;
> > + ....
> > + gr3d {
> > + compatible = "nvidia,tegra30-gr3d";
> > + nvidia,memory-clients = <&smmu TEGRA_SWGROUP_NV
> > + TEGRA_SWGROUP_NV2>;
>
> Why one cell for the host1x property, and two cells for the gr3d
> property; shouldn't they be the same length?
That can vary. Even a single device node in DT can belong to multiple
software groups.
> > diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
>
> > +static u64 smmu_of_get_memory_client(struct device *dev)
>
> > + np = of_parse_phandle(dev->of_node, propname, 0);
> > + if (np != smmu_handle->dev->of_node)
> > + return ~0;
> > +
> > + prop = of_get_property(dev->of_node, propname, &bytes);
> > + if (!prop || !bytes)
> > + return ~0;
>
> of_parse_phandle_with_fixed_args() might be a good fit here, or perhaps
> require a property #smmu-cells in the SMMU node, thus allowing the
> non-fixed-length of_parse_phandle_with_args() to be used here.
I once considered of_parse_phandle_with_args() but I couldn't use that
since "#smmu-cells" needed to be fixed in smmu node, not in client
node. In this case, the number of argument(number of swgroup IDs)
varies per client device.
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